Electrical contact and conductor, and method of making

ABSTRACT

A socket contact of beryllium copper crimped on a conductor wire and having tines surrounding a socket for receiving the pin of a pin contact, and heat treated after being so crimped, hardening the socket contact, providing springiness and wear resistance to the tines, and improving conductivity of the socket contact.

finite States Patent Kehl et a1. Oct. 22, 1974 1 1 ELECTRICAL CONTACT AND [56] References Cited CONDUCTOR, AND METHOD OF MAKING UNITED STATES PATENTS [751 Inventors: Lawrence Joseph Kehl, North 2,412,447 12/ 1946 Donzichic 148/160 Riverside; Robert Gerald Janis, 2.480.280 3/1949 33 /276 T Cicero; Tedford Hollace Spaulding, 2,563,760 8/ 1951 339/358 R Norridge all of "L 3,233,211 2/1966 339/258 R 3,286,222 11/1966 Drinkwutcr 339/258 R [73] Assignee: The Bunker-Ramo Corporation,

Oak Brook Primary Examiner-Charlcs W. Lanham [22] Filed: Sept 25, 1972 Assistant Examiner-James R. Duzan Attorney, Agent, or FirmWi1liam Lohff; F. M. [21 I App]. No.: 292,044 Arbuckle Related u.s. Application Data [62] Division of Ser. No. 87,805, Nov. 9, 1970, [57] ABSTRACT ubflfldvnfld- A socket contact of beryllium copper crimped on a conductor wire and having tines surrounding a socket 1 C1 /629, 29/630 R for receiving the pin of a pin contact, and heat treated [511 int. C1 H01! 43/00 after being so erimped, hardening the socket ontact 1 1 Field of Search n 339/258, 276 R, 276 T, providing springiness and wear resistance to the tines,

339/275 2 5 630 630 and improving conductivity of the socket contact.

6 Claims, 5 Drawing Figures ELECTRICAL CONTACT AND CONDUCTOR, AND METHOD OF MAKING This is a division, of application Ser. No. 87,805, filed Nov. 9, 1970, now abandoned.

OBJECTS OF THE INVENTION The invention resides in the general field of connectors wherein the connector parts are connected and disconnected many times, and thereby subject to great deterioration.

The invention applies to both socket contacts and pin contacts in so far as the securement of the connector member is secured to the conductor wire, but it also applies particularly to socket contacts in so far as deterioration from wear is concerned.

A broad object of this invention is to provide a connector member and conductor wire to which it is secured, capable of over-coming the objections to devices of the general character set out above.

A more specific'object is to provide a connector member and conductor wire component in which unusually great electrical contact is established between the connector member and the conductor wire.

Another and more specific object, is to provide in a connector member of the foregoing character, a socket contact of unusual great tensile strength, whereby to provide greater resistance to fatigue, and to maintain greater pressure on a pin inserted into thesocket, with corresponding greater conduction relationship between the pin and socket element.

Anadditional object is to provide an electrical connector member of the foregoing character in which the socket contact is provided with increased hardness and is thus correspondingly capable of withstanding wear.

Still another object is to provide a connector member including a socket contact having greatly increased conductivity.

A further object is to provide a method of forming a connector member of the foregoing general character, which includes applying a connector member to a conductor wire, and heat treating it for providing the advantages referred to hereinabove.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawings:

FIG. 1 is a perspective, exploded view of a device incorporating a connector embodying the features of the present invention;

FIG. 2 is a large scale, side elevational, view of a socket contact and connected conductor, included in the left hand portion of FIG. 1;

FIG. 3 is an end view taken from the right of FIG. 2;

FIG. 4 is an axial sectional view taken at line 44 of FIG. 2, and including the pin of a pin contact inserted in the socket of the socket contact; and

FIG. 5 is a large scale sectional view taken at line 5-5 of FIG. 4.

Referring in detail to the accompanying drawings, attention is directed first to FIG. 1 showing one of a wide variety of instrumentalities in which the connector member of the present invention can be incorporated. In FIG. 1 an instrumentality is indicated generally at which includes two main components 12 and 14 adapted for connection together, both mechanically and electrically. The component 12 includes a mounting element 16 having a socket element 18 which includes a plurality of socket contacts 20 of the kind embodying the features of the invention and described in detail hereinbelow. The component 14 includes a mounting member or component 22 that can be telescoped over the element 16 for mechanically mounting the component 14 on the component 12.

The component 14 includes a plug element 24 including pin contacts having pins 26 insertable into the sockets 20 when the components 12 and 14 are fitted together, for establishing electrical contact engagement between the electrical elements of the two components. Such an interconnected relation is illustrated in FIG. 4.

A typical construction in which the invention can be incorporated is a pancake making machine as disclosed in the co-pending application of two of the present inventors, namely, Lawrence J. Kehl and Robert G. Janis, and another inventor, Irvin R. Triner, and assigned to the assignee of the present invention Ser. No. 79,409, filed Oct. 9, 1970, now US. Pat. No. 3,683,150. However it will be understood there are many other kinds of devices in which the invention can be incorporated.

In any case, a deteriorating effect is produced by repeated connecting and disconnecting movements of the connector parts.

The description hereinafter relates particularly to a socket contact, because of both the matter of its connection to the conductor wire and the strength of the contact itself, although it applies to a pin contact as well in relation to its securement to a conductor wire.

The socket contact 20 is an integral piece, of beryllium copper and which may be formed in-any suitable manner, such for example as by being machined.

The contact socket as disclosed herein includes a crimp pocket or barrel 28 and a tined area 30, both tubular, the latter being slotted at 32 to form a plurality of (preferably four) tines or brushes 34, which are bent or formed inwardly at the open end 36 of the socket 31.

The crimp pocket 28 is adapted for receiving a conductor ,wire 38 which preferably in installations in which the present device is to be used is of pure, or nearly pure, copper. The conductor wire 38 is a standard item and has a diameter within a standard range of variation, and the crimp pocket is dimensioned for slidably receiving the wire for ease in assembling the elements. After the wire is thus inserted, the crimped pocket is crimped, preferably at four places forming indents 40 spaced circumferentially therearound. The crimping operation produces projections or pimples 42 on the inner surface of the crimp pocket or barrel which penetrate into the body of the conductor wire.

This crimping operation displaces the material of the crimp pocket or barrel and causes a deformation or displacement of the material of the wire 38 to such an extent that any space that may have existed between the wire and the surfaces of the crimp pocket is obviated. This may be the result of deformation of the crimp pocket itself, or of the wire, or both. The projections or pimples 42 occupy a portion of the original circumferential extent of the surface of the wire, and the portions of the wire between the pimples are necessarily correspondingly displaced outwardly, filling the space that may have otherwise existed between the wire and the crimp pocket, but also, the defomiation of the crimp pocket itself tends to additionally negate any space that would previously have existed between the wire and the pocket. It has been found that after the crimping operation, and cutting the crimped and unified portion 28 and the wire, as at the line 55 of FIG. 2, and as shown in FIG. 5, it is impossible to detect, by the naked eye, where the lines between the wire and the crimped pocket exist. The meeting and unifying of the two elements of the metal are so complete as to present substantially, and what appears as, an integral item.

After the socket contact has been thus crimped on the wire, the item thus formed, including the socket contact and as much of the wire as may be handled practically, are placed in an oven and heat treated at about 600F for about 2 hours, this temperature and this time period being of course considered optimum, but of course considerable variation in both the temperature and the time period are permissible. This heat treatment sets the socket contact so as to increase its hardness and tensile strength and thereby increase the springiness of the tines or brushes 34. The heat treating operation also increases the hardness of the socket contact and serves to improve the electrical conductivity thereof.

The beryllium copper of the socket contact before the heat treating is relatively soft and lends itself readily to forming operations, such as crimping on the conductor wire 38 and working the tines 34, as forming them in. However that metal when soft does not have good tensile strength, nor does it have good wearing resistance. But its softness renders itself to effective crimping on the conductor wire. The heat treating operation hardens the socket contact so that the crimping formations on the conductor wire take a more set condition, being hardened, and thereby resist, and actually prevent, removal of the socket contact from the wire. Moreover and very importantly, the tined area 30, including the tines 34, is hardened and because of its increased tensile strength, the tines assume a springiness that is much greater than that that existed before the heat treating. For example, tests have been made in which the contact pins 28 have been inserted into and removed from the sockets 1,000,000 times without any sign of appreciable wear or fatigue on the tines.

The heat treatment does not affect the conductor wire 38, since it is of high-pure copper. The copper wire, which is in its highest purity from a commercial standpoint, remains highly conductive, and since it is relatively soft, at least from the standpoint of the crimping operation, it enables the crimping step to take full effect.

The tines are formed in, as represented in FIGS. 2 and 4, before the heat treating operation, but this condition as will be appreciated, is exaggerated in those figures. The actual difference in diameter between the contact pins 28 and the internal diameter of the socket 31 may be very small, and the flexing of the tines much less than that indicated in FIG. 4.

We claim:

1. A method of making an electrically conductive component including the steps providing a conductor wire,

providing a one-piece connector member of soft deformable material capable of being hardened by heat treating and having a crimp pocket end for receiving the conductor wire, and a socket end for receiving a mating contact, crimping the soft pocket end of the connector member on the conductor wire to deform the pocket end on the wire to form a unitary and effectively integral member, and heat treating the connector member under conditions for hardening the material of the connector to increase the hardness of the crimped pocket end and the socket end.

2. A method according to claim 1 wherein said socket end has longitudinally extending and circumferentially spaced tines, and whereby the hardness is imparted also to the tines, and increased tensile strength is imparted to the tines.

3. A method according to claim 2 which includes the step of providing a connector member of beryllium copper.

4. A method according to claim 3 wherein the heat treatment includes heating the connector member at in the neighborhood of 600F. for in the neighborhood of 2 hours.

5. A method according to claim 1 and including the step of providing a connector member of beryllium copper and a conductive wire of high-pure copper, and placing the item thus produced in the heat treatment.

nal socket, and thereafter performing the heating step. 

1. A method of making an electrically conductive component including the steps providing a conductor wire, providing a one-piece connector member of soft deformable material capable of being hardened by heat treating and having a crimp pocket end for receiving the conductor wire, and a socket end for receiving a mating contact, crimping the soft pocket end of the connector member on the conductor wire to deform the pocket end on the wire to form a unitary and effectively integral member, and heat treating the connector member under conditions for hardening the material of the connector to increase the hardness of the crimped pocket end and the socket end.
 2. A method according to claim 1 wherein said socket end has longitudinally extending and circumferentially spaced tines, and whereby the hardness is imparted also to the tines, and increased tensile strength is imparted to the tines.
 3. A method according to claim 2 which includes the step of providing a connector member of beryllium copper.
 4. A method according to claim 3 wherein the heat treatment includes heating the connector member at in the neighborhood of 600*F. for in the neighborhood of 2 hours.
 5. A method according to claim 1 and including the step of providing a connector member of beryllium copper and a conductive wire of high-pure copper, and placing the item thus produced in the heat treatmEnt.
 6. A method according to claim 2 and including the steps of forming in the tines to produce a reduced internal socket, and thereafter performing the heating step. 